Thin-disc Yb:YAG lasers have many advantages compared with diode-pumped rod-based Nd:YAG systems，such as superior beam quality, efficiency and tunability. Yb:YAG is a quasi-three-level structure crystal with low quantum of loss, thermal load, very low thermal permeability, easy to obtain high output, and can output a maximum of 100W at 1030nm，ensuring the output mode is TEM00.Thin-disc Yb:YAG lasers are aiming for the engraving and printing markets.
Theotry
The main components of device are:
Gain medium - Nd YAG
Thin disk made of Yb：YAG. The crystal shape of the thin disk laser is a sheet type.The entire crystal of thin disk is bonded to the heat sink, so the cooling efficiency of the crystal is very high. Becasue the thickness of the crystal is very thin, only a part of the pump light is absorbed by the crystals every time while it passes through the laser crystals. In order to improve its pumping efficiency, a parabolic mirror is placed at the front of the semiconductor to produce output light with high power.
Heat sink——Used for cooling crystals
Thin disk——Made of Yb：YAG
Contact material——Contact thin disk with heat sink
Pump light——Provide energy
Parabolic mirror——Improve pumping efficiency
Optical fiber
Etalon——Produce single frequency
Filter——Tuning wavelength
Feature
- High quantum efficiency
- Low heat transfer efficiency to pump light
- High thermal conductivity
Application
- Welding high strength steels
The disk Yb:YAG laser at 1030nm with powers at 2~8 kW have extremely good beam quality compared with many other industrial lasers for welding. Yb:YAG is usually used laser medium for thin disk lasers because it has radiative lifetime and high thermal conductivity and good mechanical properties. What’s more, according to absorptivity research of materials,the disk lasers have more advantages than CO2 lasers and Nd:YAG lasers.
Leave a Reply